Effects of fixed orthodontic appliances on subgingival microflora.

OBJECTIVES: Fixed orthodontic appliances cause plaque accumulation around bands and brackets. Since the microbiological composition of dental plaque is closely connected to periodontal tissue health, the aim of this study was to determine the effects of fixed orthodontic appliances on subgingival microflora and periodontal status. METHODS: This prospective study was carried out on 32 adolescents scheduled for fixed orthodontic treatment. Subgingival dental plaque samples and periodontal records (pocket probing depth and clinical attachment level) were obtained in four recording times: before bonding of fixed appliances (T0), 1 (T1), 3 (T2) and 6 (T3) months after the beginning of orthodontic therapy, in order to detect the changes in periodontopathic anaerobe microbial flora and its effects on periodontal status. RESULTS: The values of pocket probing depth, total number of microorganisms and number of patients with positive findings of Prevotella intermedia and other periodontopathic anaerobes increased from T0 to the maximum obtained in T2 recording time. Both clinical and microbiological values decreased 6 months after the beginning of orthodontic therapy. CONCLUSIONS: The therapy with fixed appliances may transitionally increase the growth of periodontopathogenic bacteria and consequently result in gingival inflammatory response but without destructive effect on deep periodontal tissues.

Clinical and microbiological effects of fixed orthodontic appliances on periodontal tissues in adolescents.

OBJECTIVE: To determine the effects of fixed orthodontic appliances on periodontal health and microbiological composition of subgingival dental plaque. MATERIAL AND METHODS: This prospective longitudinal self-controlled study was conducted on 32 adolescents (13 males, 19 females), who were scheduled for fixed orthodontic treatment between 2002 and 2005. Dental plaque accumulation, gingival inflammation and pocket probing depth were measured at the mesio-vestibular angle of the examined group of teeth followed by collection of subgingival dental plaque samples in the same points. These periodontal indices and microbiological parameters were determined prior to the placement of fixed appliances and 1, 3 and 6 months after the beginning of orthodontic treatment. RESULTS: All values of both clinical and microbiological parameters started to increase after the placement of fixed appliances. Maximum values were reached 3 months after fixed appliance placement followed by their decrease in the last registration period of 6 months after the placement of fixed appliances. CONCLUSIONS: Treatment with fixed appliances in adolescents may transitionally increase the values of all periodontal indices and stimulate the growth of periodontopathogenic bacteria, but without destructive effects on deep periodontal tissues.

A dental implant: aluminium trioxide exhibited no effect on mouse reproductive and mutanogenic potential.

Several diseases as well as trauma can affect the composition and integrity of periodontal tissues leading eventually to the destruction of connective tissue matrix and cells, loss of attachment and resorption of alveolar bone, often followed by tooth loss. Replacement of the missing tooth could then be provided by endosseous dental implants healing in a form of osseo- or fibrosteal integration to the alveolar bone. Aluminium oxide ceramics, a form of endosseous implant, allows osseointegration type of healing and has demonstrated excellent biocompatibility. However, potential aluminium toxicity has been implicated in the pathogenesis of a number of clinical disorders and for this reason we examined the reproductive and mutagenic effect of aluminium trioxide ceramic implant in experimental mice. 720 female and 45 fertile male BALB-cAn NCR mice were included in the study. 3 experimental groups of fertile male mice (15 for each group) were treated with an intraperitoneal injection of aluminium trioxide (1 g/ kg of body weight, group I), with ethyl-methane-sulphonate as a positive control (200 mg/kg, group II) and with Tween-80 (10 mg/kg as a negative control, Group III). Each of the labeled male mice fertilized previously uncoupled female mice during 8 weeks (a pair per week) to facilitate appropriate pre- and post-meiotic conditions of spermatogenesis to occur. Female mice were sacrificed with cervical dislocation at day 13 after fertilization. Immediately upon sacrifice the uterus was removed and the number of alive and healthy, or alive but mutated and/or dead embryos was computed to determine the dominant lethal or mutagenic effect. Animals treated with aluminium trioxide demonstrated similar effects on the reproductive and mutagenic capacity as the negative control, whereas the animals treated as positive controls exhibited significantly reduced reproductive and mutagenic capacity. Collectively, we concluded that aluminium trioxide has a very low rate of embryonal mortality and mutagenicity in mice. This finding is in general agreement with the biocompatibility of aluminium trioxide as an implant material.

The neurovascular relationships and the blood supply of the trochlear nerve: surgical anatomy of its cisternal segment.

We examined in detail the cisternal segments of 15 trochlear nerves in brain stems injected with India ink and fixed in formalin. The nerves were found to emerge as singular trunks (33.3%), singular trunks with accessory rootlets (13.3%), or two or three roots with (26.7%) or without accessory rootlets (26.7%). The nerves were in close relationship or in contact with the superior cerebellar artery, that is, with the main trunk of the superior cerebellar artery, its medial and lateral terminal stems, the accessory superior cerebellar artery, and the vermian, paravermian, collicular, and lateral hemispheric arteries as well as their small branches. Some of these vessels were connected by anastomoses in 86.7% of the cases. The anastomotic channels varied from 40 to 530 microns in diameter. The cisternal segment of each trochlear nerve was usually supplied by a single long artery, which most often arose from the vermian artery (26.7%) or the collicular artery (26.7%). The feeding vessel ranged from 30 to 80 microns in caliber. We discuss the possible clinical significance of the anatomic data observed in the present study.

[Analysis of modified laterally positioned flap]. / Primena modifikovanog lateralno pomerenog reznja u lecenju mukogingivnih defekata.

The aim of this study was to investigate the effects of the covering of denuded root surfaces by the use of modified laterally positioned flap (MLPF) and application of supersaturated citric acid of pH 1. The following measurements were carried out: the width of attached gingiva, attachment of epithelium level, gingival recession, and plaque and gingival indices. The surface area of the exposed root was also measured. All measurements were made before MLPF and one, three, six and twelve months after the treatment. The average surface area of the gingival recession before surgery was 15.75 mm2 and one year after the treatment 4.20 mm2. This means that 73.30% of the denuded surfaces were covered. After the application of MLPF there was a statistically significant decrease of dental plaque index values and of gingival index values. The epithelium attachment was on the coronal level. Gingival recession was significantly decreased. The width of attached gingiva was statistically increased. It can be concluded that MLPF after the application of citric acid is a useful surgical procedure in the covering of denuded root surfaces.

[Use of intracoronal splints in therapy of periodontal disease]. / Primena intrakoronarnih kompozitnih udlaga u terapiji obolelih od parodontopatije.

The study concerns the evaluation of the efficacy of intracoronal composite splints (ICS) in the therapy of periodontal disease in its full clinical state. Maxillar and mandibular front teeth were splinted over the period of 12 weeks as a part of a complex therapy procedure of developed periodontal disease. The results of the therapy were evaluated using periodontal indexes, parameters for oral hygiene and other relevant clinical parameters. Values were processed with Student's t-test. With the use of ICS very good results in the therapy of periodontal disease in a short period of time were obtained. Parameter values decreased, especially the index of tooth mobility: before therapy by 2.84 and after therapy to 1.12. Intracoronal composite splints, in comparison with other type of splinting, satisfy both functional and aesthetic aspects.

[Microbiological investigation of supragingival dental plaque in patients treated with porcelain jacket and gold veneered resin crowns]. / Mikrobioloska istrazivanja supragingivnog dentalnog plaka u pacijenata zebrinutih porcelanskim i fasetiranium krunicama.

The majority of periodontologists agree that the primary aetiological factor of periodontal disease is dental plaque. The purpose of the study was to investigate the accumulation of dental plaque on the with porcelain jackets and gold veneered resin crowns, and to correlate these findings with the data obtained on the uncrowned control teeth in the same patients. The qualitative analysis of microorganisms in dental plaque did not show a great difference between porcelain jacket and gold veneered resin crowns. However, a high difference was found in the quantitative accumulation of microorganisms in the mature dental plaque (considerably less on porcelain jacket crowns). These findings indicate that dental porcelain is less susceptible to accumulation of bacterial plaque in comparation to resin and even to hard tooth structures.

[Microscopic analysis of gingival inflammatory infiltrate in periodontal disease]. / Mikroskopska analiza zapaljenskih infiltrata gingive u obolelih od parodontopatije.

Twenty surgically treated patients (aged 14-67) were subject of analysis aiming to found localisation, intensity and cellular structure of gingival inflammatory infiltrate. Results of our research showed following characteristics of inflammatory infiltrate: location--30% superficial, 85% deep (focal) and 30% diffused infiltrate; intensity--15% weak, 40% moderate and 45% strong infiltrate; structure--60% mainly plasmocits, 20% plasmocitis and 20% mixed inflammatory infiltrate. In sulcular epithelium were very often found large amounts of granulocits and lymphocits. It can be concluded that periodotal type of gingival inflammation had local immunologic reaction. This process was mainly located in deep parts of gingival tissue and was also predominantly alterative.

Effects of oral hygiene on periodontal tissues in a town in Yugoslavia.

We examined 1316 pupils, average age 16.6 years, in a small town in Serbia. The purpose of this study was to find out the effects of the oral hygiene on the condition of the periodontal tissues and the frequency of gingivitis and periodontal disease and their severity in this age group. The presence and quantity of dental plaque were registered according to the Silness & Löe Plaque Index. The amount of dental calculus was determined according to the Greene & Vermillion method. The condition of periodontal tissues was evaluated by Ramfjord's method. It was found that only 5.3% of the examined pupils had a clinically healthy periodontium. Gingivitis was discovered in 60.6%, and periodontal disease (with periodontal pockets) in 34.1% of the examined pupils. The average PDI was 1.8. We revealed great quantities of soft and hard deposits on the teeth of examined pupils. The average Plaque Index was very high (1.9).